Despite its increasing importance, the verification and validation of the human-machine interface is perhaps the most overlooked aspect of system development. Although much has been written about the design and developmentprocess, very little organized information is available on how to verifyand validate highly complex and highly coupled dynamic systems. Inability toevaluate such systems adequately may become the limiting factor in our ability to employ systems that our technology and knowledge allow us to design. This volume, based on a NATO Advanced Science Institute held in 1992, is designed to provide guidance for the verification and validation of all highly complex and coupled systems. Air traffic control isused an an example to ensure that the theory is described in terms that will allow its implementation, but the results can be applied to all complex and coupled systems. The volume presents the knowledge and theory ina format that will allow readers from a wide variety of backgrounds to apply it to the systems for which they are responsible. The emphasis is on domains where significant advances have been made in the methods of identifying potential problems and in new testing methods and tools. Also emphasized are techniques to identify the assumptions on which a system is built and to spot their weaknesses.